A known device of this type exists, which has at least two pedicle screws, each of which has a first end connected with a corresponding vertebral body, a swollen intermediate portion, as well as a second threaded end. Auxiliary components, provided with a bow for attachment of a rod extending between the vertebrae, are arranged on each of the aforementioned swollen portions. A bolt, which cooperates with the threaded end of each screw, makes possible the immobilization of each auxiliary component, once the latter is positioned in the appropriate manner.
This known device nevertheless has certain disadvantages, in that it involves a relatively delicate assembly process. Furthermore, once implanted, it offers no degree of freedom between the different elements of which it consists. Thus, when forces are exerted on the vertebral bodies, this absence of degree of freedom induces a transmission of these forces over the whole device, so that the latter has a tendency to become disconnected from the vertebrae which it connects and furthermore induces malfunctionings with regard to the whole vertebral chain.